A fiddler crab, sometimes known as a calling crab, may be any of approximately 97 species of semi-terrestrial marine crabs within the genus Uca . Belonging to the family Ocypodidae, fiddler crabs are most closely related to the ghost crabs of the genus Ocypode. This crustacean is named for the fiddle-shaped large claw of the male crab. This entire group is composed of small crabs – the largest being slightly over two inches across. Fiddler crabs are... (From Wikipedia)